1) `list` auto-update was deleting the old message every time, now it (and `summary`) edits the existing message(s) when auto-updating *unless* the auto-update message isn't the most recent. If there are newer messages then the auto-update is deleted and reposted at the bottom
2) depending on the timing with which a user presses the "cancel" reaction to stop auto-update, it could be missed. Added a final check based on the count of the cancel reaction. This has the drawback that any user can cancel the auto-update, but I could check to make sure the message author is one of the people that pressed it.
When auto-updating `summary`, reactions were not being removed for listing types of transfers of which there were none. Now that's fixed. e.g. if the number of downloading transfers goes from 1 to zero, the downloading reaction will be removed the next time the output is updated.
Repeat option for `summary` and `list` commands
More filters: stalled, running (non-zero rate), error (and types of error), verifying data, queued, public/private (tracker)
Added option to verify data to `modify` command
Added more info to summary.